Outside side-stripping device

ABSTRACT

This disclosure relates to a mechanism for side-stripping can bodies utilizing a spray gun moving in a direction opposite to the direction of movement of a can body to provide a thin striping or coating on the side seam thereof. The striping apparatus includes a synchronizing mechanism which is in engagement with a conveyor chain moving the can bodies to be side striping and which varies the position of the control mechanism of the side striping apparatus in accordance with the variations in the links or other constructional elements of the conveyor chain.

United States Patent Galitz [151 3,654,898 [451 Apr. 11, 1972 [54] OUTSIDE SIDE-STRIPPING DEVICE [72] Inventor: Raymond F. Galitz, La Grange Park, 111.

[73] Assignee: Continental Can Company, Inc., New

York, NY.

[22] Filed: July 17, 1970 21 Appl. No.: 55,655

[52] U.S. Cl ..ll8/323, 118/324, 198/162 51 Int. Cl ..B05b 9/06 [58] Field of Search ..l18/320, 321, 322, 323, 324, 118/301 [56] References Cited UNITED STATES PATENTS 1,868,850 7/1932 Purinton ..1 18/323 2,145,861 2/1939 Casto ..l18/323 3,383,046 5/1968 Voegtly ..11s/323 2,996,040 8/1961 Bofinger ..1l8/301 Primary Examiner-Mervin Stein Assistant Examiner-Leo Millstein Attorney-Diner, Brown, Ramik & Holt [5 7] ABSTRACT This disclosure relates to a mechanism for side-stripping can bodies utilizing a spray gun moving in a direction opposite to the direction of movement of a can body to provide a thin striping or coating on the side seam thereof. The striping apparatus includes a synchronizing mechanism which is in engagement with a conveyor chain moving the can bodies to be side striping and which varies the position of the control mechanism of the side striping apparatus in accordance with the variations in the links or other constructional elements of the conveyor chain.

11 Claims, 1 Drawing Figure PATENTEDAFR 11 I972 3,654,898

INVENTOR RAYMOND F. GQUTZ,

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ATTORNEYS OUTSIDE SIDE-STRIPPING DEVICE BACKGROUND OF THE INVENTION Experimentation has established the desirability of using a hot-melt lacquer formulation for the side striping of can bodies, thus eliminating the need for prolonged drying with heat which is necessary for lacquers containing solvents. It has also been determined that the conventional stationary spray gun, with can bodies being conveyed thereover at normal sideseamer speeds, produces a stripe too thick when using hotmelt lacquers even when the smallest practical gun orifice (0.002 inch X 0.375 inch) is used. In order to reduce the thickness of the side-stripe, it is proposed to provide a traveling gun, which gun will travel in the opposite direction of the can body travel at a speed that will result in the spray gun traversing the length of the can body in about l/lOth of the time required for a stationary spray gun. This increase in speed, together with a traveling gun, makes complicated or impractical conventional electro-pneumatic gun triggering devices.

It is to be understood that since a traveling gun is a requirement, it can be readily mechanically actuated as it passes a stationary cam. This cam can be adjustably positioned and adjustable for spray time so as to start and stop the spray in proper relation to the cam length. However, there is another factor involved which prevents these adjustments alone to suffice.

It is to be understood that the can bodies are conveyed by an endless conveyor chain. It is further to be understood that even in high precision chains, there are variations in link lengths so that even when conveying lugs are accurately positioned on the chain, when a conveying lug approaches the spraying zone, its spacing from the axis of the drive sprocket for the conveyor chain will vary. Further, as the chain becomes worn, it wear differentially between the lugs causing further variations. This has been chronically troublesome and is the reason electronic can detection is used in many installations.

However, with a traveling gun, electronic can detection becomes complicated. Furthermore, a lag-free cam operated gun is more desirable.

SUMMARY OF THE INVENTION In accordance with this invention, it is proposed to move the spray guns in a direction opposite to the direction of can body travel. As stated above, this provides for a very high speed spraying operation with a very thin coating being applied to the can body.

It is also proposed to utilize a cam for directly actuating each spray gun as it moves through the spraying zone. On the other hand, it is not proposed to have the cam stationarily mounted, but to mount it for oscillatory movement in accordance with the variations in the construction of the endless conveyor chain which moves the can bodies. By mechanically detecting the variations in the can body conveyor chain' and translating these variations into movement of the cam, an automatic compensation may be provided for the conveyor chain variations.

In accordance with this invention, the cam for actuating the spray guns is mounted for limited guided movement parallel to that portion of the run of the can body conveyor which is in the spraying zone. The support for the cam carries a sprocket which is meshed with the portion of the conveyor chain run in the spraying zone. Drive means are provided for rotating both this sprocket and the drive sprocket for the can body conveyor chain at the same peripheral speed. Variations in the construction of the conveyor chain will result in momentary acceleration and de-acceleration of the link meshed with this added sprocket with the result that the sprocket will oscillate along the conveyor chain run and thus effect minute oscillation of the cam in accordance with the variations in the conveyor chain. Thus, this sprocket will effect the synchronizing of the can bodies conveyed by the conveyor chain with the cam so as to fully compensate for variations in the construction of the conveyor chain.

With the above and other objects in view that will hereinafter appear, the nature of the invention will be more clearly understood by reference to the following detailed description, the appended claims and the view illustrated inthe accompanying drawing:

The drawing is a schematic side elevational view of a practical embodiment of the invention.

Referring now to the drawing in detail, it will be seen that there is illustrated a conventional side seamer conveyor chain 5 which is an endless chain and which is entrained over a drive sprocket 6 and an idler sprocket 7.

The conveyor chain 5 has a run 8 which is disposed in parallel cooperating relation with respect to a guide 10 for can bodies C. The conveyor chain 5 is provided with a plurality of lugs 11 which are equally spaced as closely as possible with the construction of the conveyor chain 5 so as to serially move can bodies C along the guide 10.

As each can body C is moved through a spraying zone, generally identified by the numeral 12, a narrow stripe-coating is applied over the side seam thereof by a traveling spray gun 13 which is preferably of the same construction as the spray gun disclosed in my copending application entitled Traveling Outside Side-Striping Spray Gun filed on even date herewith. The spray guns 13, of which only one has been illustrated, will be mounted for continuous movement with a portion of the movement of each spray gun 13 being a straight line movement parallel to and in alignment with the movement of the can bodies C through the spray zone 12 and in a direction opposite to the direction of movement of the can bodies C.

For simplicity, the spray gun 13 is illustrated as being carried by an endless chain 14 which is entrained on a pair of spaced sprockets 15 and 16 of which one of the sprockets will be a drive sprocket. It is, however, preferred that the spray guns 13 be mounted on a suitable turret in a manner wherein during the movement of each spray gun 13 through the spray zone 12, the movement of the spray gun will be a straight line movement. The details of the mounting of the spray gun and movement thereof is not a part of this invention and will not be described in more detail here.

Each spray gun 13 is provided with a control arm 17 which, in turn, carries a cam follower 18 for cooperation with a cam, generally identified by the numeral 20, to effect the pivoting of the control arm 17 and the actuation of the spray gun 13.

The cam assembly 20 includes a mounting plate 21 on which a spray initiating cam segment 22 is mounted for vertical movement by suitable means, such as the illustrated pin and slot connections 23. The cam assembly 20 further includes a spray stopping cam 24 which is fixedly mounted on the plate 21.

It will be readily apparent that the cam assembly 20 may be constructed and positioned so as to initiate the action of the spray gun 13 at a predetermined point in its travel through the spray zone 12 and, in a like manner, to discontinue the spray action at a longitudinally spaced point in the spray zone 12. It is also possible to correlate the points of spray initiation and spray stoppage with predetermined positions of the leading edge and a trailing edge of a can body C passing through the spray zone 12. Thus, if the can bodies C were moved uniformly through the spray zone 12, the fixed cam assembly 20 would suffice. However, because the can bodies cannot be uniformly moved through the spray zone 12 due to the constructional variations in the conveyor chain 5, it is necessary to compensate for these variations and to synchronize the operation of the spray gun with the actual positions of the individual can bodies as they pass through the spray zone 12.

In accordance with this invention, the cam assembly 20 is mounted on a suitable guide structure, which may be in the form of guide rods 25 for limited guided movement parallel to that portion of the conveyor chain run 8 which is in the spray zone 12. A support arm 26 is rigidly connected to and extends upwardly from the plate 21 and carries for rotation a sprocket 27 which is in meshing engagement with that portion of the conveyor chain run 8 which is disposed within the spray zone 12. In accordance with this invention, the sprocket 27 is driven at the same peripheral rate as the drive sprocket 6 for the conveyor chain 5. Therefore, if the conveyor chain were of a uniform construction and there would be no variation in the movement of the can bodies C through the spray zone 12, the sprocket 27 would remain stationary and would merely move in unison with the conveyor chain 5. However, because the sprocket 27 is driven, when there is any variation in the relative position of a link of the conveyor chain 5 from the axis of rotation of the sprocket 6, there is a tendency for the conveyor chain 5 to either speed up or slow down the rotation of the sprocket 27. Since the sprocket 27 is independently driven, this cannot occur. As a result, the sprocket 27 is shifted longitudinally of the conveyor chain run 8 in accordance with the variation in the construction of the conveyor chain. The net result is that the sprocket 27 substantially continuously oscillates and since it is positively connected to the cam assembly 20, the cam assembly 20 also oscillates. This oscillation of the cam assembly 20 in synchronism with the variations in the construction of the chain 5 fully compensates for the variations in the movement of the can bodies C through the spray zone 12 and permits the alignment of the spray initiation with the leading edge of the can body and the spray stopping with the trailing edge of the can body being side striped.

in the drawing, a very simple form of drive for the sprocket 27 has been illustrated. If desired, the sprocket 27 may be a double row sprocket and therefore, would include a second and identical sprocket element 28. A drive chain 30 is entrained over the sprocket element 28 so as to effect rotation of the sprocket elements 27 and 28. The drive chain 30 would also be entrained over a drive sprocket 31. The drive sprocket 31 would be mounted for rotation about a fixed axis as determined by the shaft 32 while the sprocket elements 27 and 28 would be free to oscillate along the conveyor chain run 8.

A common drive would be provided for the drive sprockets 6 and 31, which common drive is illustrated schematically as including a drive shaft 32 which, in turn, is coupled by a suitable coupling element 33 to the drive sprocket 6. It would also be desirable for the drive shaft 32 to be coupled to the sprocket 16, for example, or for a turntable shaft in the case the spray guns 13 are carried by a turret, so as to synchronize the movement of the spray guns 13 with the movement of the can bodies C.

Referring once again to the vertical movement of the cam segment 22, it is to be noted that the position of the cam segment 22 is controlled by means of a motor element 34 which may be in the form of a fluid cylinder or a solenoid. A conventional can body detector 35 would appropriately be positioned adjacent the spray zone 12 for controlling the actuation of the motor 34 in a known manner. Normally the cam segment 22 would be in its elevated gun actuating position. However, when the detector 35 indicates the absence of a can body, the motor 34 would be actuated to retract the cam segment 22. Then, as a spray gun 13 passes through the spray zone 12, the cam follower 18 thereof would not engage the cam segment 22 and spraying would not be initiated.

Although it has not been specifically illustrated in the drawing, if desired, the plate 21 could have an adjustable connection with the mounting bracket 26 which would permit relative adjustment between the cam assembly 20 and the sprocket 27.

Although only a preferred embodiment of the invention has been specifically illustrated and described herein, it is to be understood that minor variations may be made therein without departing from the spirit and scope of the invention,

as defined by the appended claims.

I claim:

1. In combination with an endless chain conveyor of the type including a chain, a drive sprocket and an operative run; and an apparatus actuatable in timed relation with the movement of a portion of said run; a synchronizing mechanism for compensating for variations in the construction of said chain: said synchronizing mechanism comprising sprocket means meshing with said chain run portion and mounted for oscillatory movement along said run in accordance with variations in said chain, drive means coupled to said drive sprocket and said sprocket means for driving the same at the same peripheral rate whereby said sprocket means oscillates directly in accordance with the variations in said chain as such variations pass said run portion, and means coupling said apparatus to said sprocket means for direct movement therewith.

2. The combination of claim 1 wherein said apparatus includes a normally stationary control device, and said control device is connected to said sprocket means for oscillatory movement therewith.

3. The combination'of claim 2 wherein said control device is a-cam.

4. The combination of claim 2 wherein said control device is a cam, and said apparatus includes a further device moving alongside said run portion and having controls actuated by engagement with said cam.

5. The combination of claim 1 wherein said drive means includes a second chain driven by a second drive sprocket and drivingly connected to said sprocket means, said second drive sprocket being mounted for rotation about a fixed axis.

6. The combination of claim 5 wherein said drive means includes a common drive for said drive sprockets.

7. The combination of claim 1 wherein said conveyor chain is particularly adapted to convey tubular bodies of the type having side seams, said apparatus is a seam striping apparatus including a traveling spray gun, and a normally stationary control device for said spray gun, said control device being con-.

nected to said sprocket means for oscillatory movement therewith.

8. The combination of claim 7 wherein said spray gun is cam actuated and said control device is a cam.

9. The combination of claim 7 wherein said spray gun moves in an opposite direction from the direction of body movement whereby a fast relative movement between a spray gun and a tubular body being coated may be effected to thinly apply a thicker than desired spray of material.

10. The combination of claim 7 wherein means are provided for supporting said spray gun for continuous movement about an endless path.

11. The combination of claim 7 wherein said spray gun is cam actuated and said control device is a cam, said cam including a spray actuating segment mounted for movement to an inoperative position, and a no body-no spray mechanism connected to said cam segment for moving said cam segment to said inoperative position in the absence of a body to receive a spray from said spray gun, 

1. In combination with an endless chain conveyor of the type including a chain, a drive sprocket and an operative run; and an apparatus actuatable in timed relation with the movement of a portion of said run; a synchronizing mechanism for compensating for variations in the construction of said chain: said synchronizing mechanism comprising sprocket means meshing with said chain run portion and mounted for oscillatory movement along said run in accordance with variations in said chain, drive means coupled to said drive sprocket and said sprocket means for driving the same at the same peripheral rate whereby said sprocket means oscillates directly in accordance with the variations in said chain as such variations pass said run portion, and means coupling said apparatus to said sprocket means for direct movement therewith.
 2. The combination of claim 1 wherein said apparatus includes a normally stationary control device, and said control device is connected to said sprocket means for oscillatory movement therewith.
 3. The combination of claim 2 wherein said control device is a cam.
 4. The combination of claim 2 wherein said control device is a cam, and said apparatus includes a further device moving alongside said run portion and having controls actuated by engagement with said cam.
 5. The combination of claim 1 wherein said drive means includes a second chain driven by a second drive sprocket and drivingly connected to said sprocket means, said second drive sprocket being mounted for rotation about a fixed axis.
 6. The combination of claim 5 wherein said drive means includes a common drive for said drive sprockets.
 7. The combination of claim 1 wherein said conveyor chain is particularly adapted to convey tubular bodies of the type having side seams, said apparatus is a seam striping apparatus including a traveling spray gun, and a normally stationary control device for said spray gun, said control device being connected to said sprocket means for oscillatory movement therewith.
 8. The combination of claim 7 wherein said spray gun is cam actuated and said control device is a cam.
 9. The combination of claim 7 wherein said spray gun moves in an opposite direction from the direction of body movement whereby a fast relative movement between a spray gun and a tubular body being coated may be effected to thinly apply a thicker than desired spray of material.
 10. The combination of claim 7 wherein means are provided for supporting said spray gun for continuous movement about an endless path.
 11. The combination of claim 7 wherein said spray gun is cam actuated and said control device is a cam, said cam including a spray actuating segment mounted for movement to an inoperative position, and a no body-no spray mechanism connected to said cam segment for moving said cam segment to said inoperative position in the absence of a body to receive a spray from said spray gun. 